Problem: Solve for $y$ : $-29 + y = -19$
Solution: Add $29$ to both sides: $ \begin{eqnarray} \\ -29 + y &=& -19 \\ \\ {+29} && {+29} \end{eqnarray} $ $ \begin{eqnarray} \hphantom{-29 + y} &\hphantom{=}& \hphantom{-19} \\ y &=& -19 {+ 29} \\ \end{eqnarray} $ Simplify. $ y = 10$